FAILURE MAP
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FA-89001 / Digital logic simulation / Open access

Fault detection observes only the first primary output · case 01

Faults that propagate only to later outputs are reported as undetected.

Verified by executionVariant 1 · 9 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The faulty and good responses are compared on the first primary output only.

THE FAILURE

The faulty and good responses are compared on the first primary output only.

Unsuccessful approach: Watching only the last output misses faults that reach only the first output.

Case contract

Input [pis, gates, pos, vectors, faults]. Gates [out, op, ins] are topologically ordered (and/or/nand/nor/not). A fault [net, None, v] is a stem stuck-at on a primary input or gate output; [net, reader, v] is a branch fault that forces only the pin of gate 'reader' that reads 'net'. A fault is detected by a vector when any primary output differs from the fault-free circuit. Return [net, reader, v, first detecting vector index or None] per fault.

Why this case matters

Fault simulators grade test sets; stem/branch distinction and output comparison determine reported coverage.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(*args):
    pis, gates, pos, vectors, faults = args
    def ev(op, bits):
        if op == 'and': return int(all(bits))
        if op == 'or': return int(any(bits))
        if op == 'nand': return 1 - int(all(bits))
        if op == 'nor': return 1 - int(any(bits))
        return 1 - bits[0]
    def sim(vec, fault):
        net, pin, sv = fault if fault else (None, None, None)
        val = {}
        for p in pis:
            val[p] = sv if (p == net and pin is None) else vec[p]
        for out, op, ins in gates:
            bits = [sv if (i == net and pin == out) else val[i] for i in ins]
            v = ev(op, bits)
            val[out] = sv if (out == net and pin is None) else v
        return [val[o] for o in pos]
    res = []
    for f in faults:
        first = None
        for idx, vec in enumerate(vectors):
            if sim(vec, f)[0] != sim(vec, None)[0]:
                first = idx
                break
        res.append([f[0], f[1], f[2], first])
    return res
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('primary input stuck-at-1', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}], [['a', None, 1]]], [['a', None, 1, 1]]), ('primary input stuck-at-0', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}], [['b', None, 0]]], [['b', None, 0, 1]]), ('fanout branch fault into n4', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}], [['n1', 'n4', 1]]], [['n1', 'n4', 1, 5]]), ('fanout branch fault into n2', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}], [['n1', 'n2', 0]]], [['n1', 'n2', 0, 1]]), ('fault visible only at the second output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}], [['n4', None, 1]]], [['n4', None, 1, 0]]), ('fault visible only at the first output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}], [['n2', None, 0]]], [['n2', None, 0, 0]]), ('stem fault on internal net', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['n1', None, 0], ['n3', None, 0]]], [['n1', None, 0, 0], ['n3', None, 0, 2]]), ('branch fault masked on its reader', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}], [['n1', 'n4', 0]]], [['n1', 'n4', 0, None]]), ('input fault masked downstream', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['c', 'n5', 1]]], [['c', 'n5', 1, 1]])], [('primary input stuck-at-1', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['a', None, 1]]], [['a', None, 1, 0]]), ('primary input stuck-at-0', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['b', None, 0]]], [['b', None, 0, 0]]), ('fanout branch fault into n4', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['n1', 'n4', 1]]], [['n1', 'n4', 1, 4]]), ('fanout branch fault into n2', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['n1', 'n2', 0]]], [['n1', 'n2', 0, 0]]), ('fault visible only at the second output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['n4', None, 1]]], [['n4', None, 1, 2]]), ('fault visible only at the first output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['n2', None, 0]]], [['n2', None, 0, 0]]), ('stem fault on internal net', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['n1', None, 0], ['n3', None, 0]]], [['n1', None, 0, 1], ['n3', None, 0, 3]]), ('branch fault masked on its reader', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 0}], [['n1', 'n4', 0]]], [['n1', 'n4', 0, None]]), ('input fault masked downstream', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['c', 'n5', 1]]], [['c', 'n5', 1, 0]])], [('primary input stuck-at-1', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['a', None, 1]]], [['a', None, 1, 0]]), ('primary input stuck-at-0', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['b', None, 0]]], [['b', None, 0, 0]]), ('fanout branch fault into n4', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['n1', 'n4', 1]]], [['n1', 'n4', 1, 3]]), ('fanout branch fault into n2', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['n1', 'n2', 0]]], [['n1', 'n2', 0, 1]]), ('fault visible only at the second output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['n4', None, 1]]], [['n4', None, 1, 1]]), ('fault visible only at the first output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['n2', None, 0]]], [['n2', None, 0, 0]]), ('stem fault on internal net', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['n1', None, 0], ['n3', None, 0]]], [['n1', None, 0, 0], ['n3', None, 0, 4]]), ('branch fault masked on its reader', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}], [['n1', 'n4', 0]]], [['n1', 'n4', 0, None]]), ('input fault masked downstream', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['c', 'n5', 1]]], [['c', 'n5', 1, 1]])], [('primary input stuck-at-1', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['a', None, 1]]], [['a', None, 1, 6]]), ('primary input stuck-at-0', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['b', None, 0]]], [['b', None, 0, 2]]), ('fanout branch fault into n4', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['n1', 'n4', 1]]], [['n1', 'n4', 1, 2]]), ('fanout branch fault into n2', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['n1', 'n2', 0]]], [['n1', 'n2', 0, 0]]), ('fault visible only at the second output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['n4', None, 1]]], [['n4', None, 1, 0]]), ('fault visible only at the first output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['n2', None, 0]]], [['n2', None, 0, 0]]), ('stem fault on internal net', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['n1', None, 0], ['n3', None, 0]]], [['n1', None, 0, 0], ['n3', None, 0, 5]]), ('branch fault masked on its reader', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 0}], [['n1', 'n4', 0]]], [['n1', 'n4', 0, None]]), ('input fault masked downstream', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}], [['c', 'n5', 1]]], [['c', 'n5', 1, 0]])], [('primary input stuck-at-1', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['a', None, 1]]], [['a', None, 1, 5]]), ('primary input stuck-at-0', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['b', None, 0]]], [['b', None, 0, 1]]), ('fanout branch fault into n4', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['n1', 'n4', 1]]], [['n1', 'n4', 1, 1]]), ('fanout branch fault into n2', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['n1', 'n2', 0]]], [['n1', 'n2', 0, 3]]), ('fault visible only at the second output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['n4', None, 1]]], [['n4', None, 1, 0]]), ('fault visible only at the first output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['n2', None, 0]]], [['n2', None, 0, 0]]), ('stem fault on internal net', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}], [['n1', None, 0], ['n3', None, 0]]], [['n1', None, 0, 0], ['n3', None, 0, 6]]), ('branch fault masked on its reader', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}], [['n1', 'n4', 0]]], [['n1', 'n4', 0, None]]), ('input fault masked downstream', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}], [['c', 'n5', 1]]], [['c', 'n5', 1, None]])]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
primary input stuck-at-1[['a', None, 1, 1]][['a', None, 1, 1]]Passed
primary input stuck-at-0[['b', None, 0, 5]][['b', None, 0, 1]]Failed
fanout branch fault into n4[['n1', 'n4', 1, None]][['n1', 'n4', 1, 5]]Failed
fanout branch fault into n2[['n1', 'n2', 0, 1]][['n1', 'n2', 0, 1]]Passed
fault visible only at the second output[['n4', None, 1, None]][['n4', None, 1, 0]]Failed
fault visible only at the first output[['n2', None, 0, 0]][['n2', None, 0, 0]]Passed
stem fault on internal net[['n1', None, 0, 0], ['n3', None, 0, None]][['n1', None, 0, 0], ['n3', None, 0, 2]]Failed
branch fault masked on its reader[['n1', 'n4', 0, None]][['n1', 'n4', 0, None]]Passed
input fault masked downstream[['c', 'n5', 1, None]][['c', 'n5', 1, 1]]Failed

SHA-256 / 1fdc8b8a1b7a42ae97bb806c87c978bf861839d8b4cff02c0935232220d46c3a

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(*args):
    pis, gates, pos, vectors, faults = args
    def ev(op, bits):
        if op == 'and': return int(all(bits))
        if op == 'or': return int(any(bits))
        if op == 'nand': return 1 - int(all(bits))
        if op == 'nor': return 1 - int(any(bits))
        return 1 - bits[0]
    def sim(vec, fault):
        net, pin, sv = fault if fault else (None, None, None)
        val = {}
        for p in pis:
            val[p] = sv if (p == net and pin is None) else vec[p]
        for out, op, ins in gates:
            bits = [sv if (i == net and pin == out) else val[i] for i in ins]
            v = ev(op, bits)
            val[out] = sv if (out == net and pin is None) else v
        return [val[o] for o in pos]
    res = []
    for f in faults:
        first = None
        for idx, vec in enumerate(vectors):
            if sim(vec, f)[-1] != sim(vec, None)[-1]:
                first = idx
                break
        res.append([f[0], f[1], f[2], first])
    return res
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('primary input stuck-at-1', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}], [['a', None, 1]]], [['a', None, 1, 1]]), ('primary input stuck-at-0', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}], [['b', None, 0]]], [['b', None, 0, 1]]), ('fanout branch fault into n4', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}], [['n1', 'n4', 1]]], [['n1', 'n4', 1, 5]]), ('fanout branch fault into n2', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}], [['n1', 'n2', 0]]], [['n1', 'n2', 0, 1]]), ('fault visible only at the second output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}], [['n4', None, 1]]], [['n4', None, 1, 0]]), ('fault visible only at the first output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}], [['n2', None, 0]]], [['n2', None, 0, 0]]), ('stem fault on internal net', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['n1', None, 0], ['n3', None, 0]]], [['n1', None, 0, 0], ['n3', None, 0, 2]]), ('branch fault masked on its reader', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}], [['n1', 'n4', 0]]], [['n1', 'n4', 0, None]]), ('input fault masked downstream', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['c', 'n5', 1]]], [['c', 'n5', 1, 1]])], [('primary input stuck-at-1', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['a', None, 1]]], [['a', None, 1, 0]]), ('primary input stuck-at-0', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['b', None, 0]]], [['b', None, 0, 0]]), ('fanout branch fault into n4', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['n1', 'n4', 1]]], [['n1', 'n4', 1, 4]]), ('fanout branch fault into n2', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['n1', 'n2', 0]]], [['n1', 'n2', 0, 0]]), ('fault visible only at the second output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['n4', None, 1]]], [['n4', None, 1, 2]]), ('fault visible only at the first output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['n2', None, 0]]], [['n2', None, 0, 0]]), ('stem fault on internal net', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['n1', None, 0], ['n3', None, 0]]], [['n1', None, 0, 1], ['n3', None, 0, 3]]), ('branch fault masked on its reader', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 0}], [['n1', 'n4', 0]]], [['n1', 'n4', 0, None]]), ('input fault masked downstream', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['c', 'n5', 1]]], [['c', 'n5', 1, 0]])], [('primary input stuck-at-1', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['a', None, 1]]], [['a', None, 1, 0]]), ('primary input stuck-at-0', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['b', None, 0]]], [['b', None, 0, 0]]), ('fanout branch fault into n4', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['n1', 'n4', 1]]], [['n1', 'n4', 1, 3]]), ('fanout branch fault into n2', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['n1', 'n2', 0]]], [['n1', 'n2', 0, 1]]), ('fault visible only at the second output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['n4', None, 1]]], [['n4', None, 1, 1]]), ('fault visible only at the first output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['n2', None, 0]]], [['n2', None, 0, 0]]), ('stem fault on internal net', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['n1', None, 0], ['n3', None, 0]]], [['n1', None, 0, 0], ['n3', None, 0, 4]]), ('branch fault masked on its reader', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}], [['n1', 'n4', 0]]], [['n1', 'n4', 0, None]]), ('input fault masked downstream', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['c', 'n5', 1]]], [['c', 'n5', 1, 1]])], [('primary input stuck-at-1', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['a', None, 1]]], [['a', None, 1, 6]]), ('primary input stuck-at-0', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['b', None, 0]]], [['b', None, 0, 2]]), ('fanout branch fault into n4', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['n1', 'n4', 1]]], [['n1', 'n4', 1, 2]]), ('fanout branch fault into n2', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['n1', 'n2', 0]]], [['n1', 'n2', 0, 0]]), ('fault visible only at the second output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['n4', None, 1]]], [['n4', None, 1, 0]]), ('fault visible only at the first output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['n2', None, 0]]], [['n2', None, 0, 0]]), ('stem fault on internal net', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['n1', None, 0], ['n3', None, 0]]], [['n1', None, 0, 0], ['n3', None, 0, 5]]), ('branch fault masked on its reader', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 0}], [['n1', 'n4', 0]]], [['n1', 'n4', 0, None]]), ('input fault masked downstream', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}], [['c', 'n5', 1]]], [['c', 'n5', 1, 0]])], [('primary input stuck-at-1', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['a', None, 1]]], [['a', None, 1, 5]]), ('primary input stuck-at-0', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['b', None, 0]]], [['b', None, 0, 1]]), ('fanout branch fault into n4', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['n1', 'n4', 1]]], [['n1', 'n4', 1, 1]]), ('fanout branch fault into n2', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['n1', 'n2', 0]]], [['n1', 'n2', 0, 3]]), ('fault visible only at the second output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['n4', None, 1]]], [['n4', None, 1, 0]]), ('fault visible only at the first output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['n2', None, 0]]], [['n2', None, 0, 0]]), ('stem fault on internal net', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}], [['n1', None, 0], ['n3', None, 0]]], [['n1', None, 0, 0], ['n3', None, 0, 6]]), ('branch fault masked on its reader', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}], [['n1', 'n4', 0]]], [['n1', 'n4', 0, None]]), ('input fault masked downstream', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}], [['c', 'n5', 1]]], [['c', 'n5', 1, None]])]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
primary input stuck-at-1[['a', None, 1, 1]][['a', None, 1, 1]]Passed
primary input stuck-at-0[['b', None, 0, 5]][['b', None, 0, 1]]Failed
fanout branch fault into n4[['n1', 'n4', 1, None]][['n1', 'n4', 1, 5]]Failed
fanout branch fault into n2[['n1', 'n2', 0, None]][['n1', 'n2', 0, 1]]Failed
fault visible only at the second output[['n4', None, 1, None]][['n4', None, 1, 0]]Failed
fault visible only at the first output[['n2', None, 0, None]][['n2', None, 0, 0]]Failed
stem fault on internal net[['n1', None, 0, 0], ['n3', None, 0, 2]][['n1', None, 0, 0], ['n3', None, 0, 2]]Passed
branch fault masked on its reader[['n1', 'n4', 0, None]][['n1', 'n4', 0, None]]Passed
input fault masked downstream[['c', 'n5', 1, 1]][['c', 'n5', 1, 1]]Passed

SHA-256 / 669044482fc7e55a7031ebc2ed6e3ef28bb49d130b479ba685b82492b1404fe2

HELD IN THE MEMBER ARCHIVE

The verified repair and its recorded checks are member-only.

This mechanism has 9 recorded checks per implementation. The open-access tier publishes the failure and the unsuccessful fix; the repaired source that passes every check, and the observations that prove it, are available to members.

Every case sharing this mechanism uses the same contract and the same repair, so this one record is held back for all of them.

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Verification & scope

A deterministic bounded teaching model of one simulator rule set; the contract is stipulated and is not a claim of conformance to any HDL standard or commercial simulator. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.

Observations recorded using Python 3.12.14 at 2026-09-29T14:51:13.497202+00:00.

Case digest / 29f0f8b2f9cbd9d08232e0699faa0ccf08901688b1c43c5b3c482dfcae856f9c